Nectarine tree named ‘Burnectthirteen’

ABSTRACT

A new and distinct variety of nectarine tree ( Prunus persica  sub species  nuciperisica ), and which is denominated varietally as ‘Burnectthirteen’, and which produces an attractively colored white-fleshed, sub-acid clingstone nectarine, which is mature for harvesting and shipment approximately May 24 to June 4 under ecological conditions prevailing in the San Joaquin Valley of Central California.

BACKGROUND OF THE NEW VARIETY

The present invention relates to a new, novel and distinct variety ofnectarine tree, Prunus persica (subspecies nucipersica), and which hasbeen denominated varietally as ‘Burnectthirteen’.

ORIGIN

The present variety of nectarine tree resulted from an on-going programof fruit and nut tree breeding. The purpose of this program is toimprove the commercial quality of deciduous fruit and nut varieties androotstocks by creating and releasing promising new selections of prunus,malus and regia species. To this end we make both controlled and hybridcross pollinations each year in order to produce seedling populationsfrom which improved progenies are evaluated and selected.

The seedling ‘Burnectthirteen’ was originated by us from a population ofseedlings grown in our experimental orchards located near Fowler, Calif.The seedlings, grown on their own roots, were the result of a controlledcross of the yellow-fleshed ‘Crimson Baby’ nectarine tree(non-patented), which was used as the seed parent, and the sub-acidicwhite fleshed nectarine tree, ‘Arctic Star’ (U.S. Plant Pat. No. 9,332)which was used as the pollen parent. One seedling, which is the presentvariety, exhibited especially desirable characteristics and wasdesignated as ‘E7.043’. This seedling was marked for subsequentobservation. After the 1998 fruiting season, the new variety ofnectarine tree was selected for advanced evaluation and repropagation.

ASEXUAL REPRODUCTION

Asexual reproduction of this new and distinct variety of nectarine treewas accomplished by budding the new nectarine tree variety to‘Nemaguard’ Rootstock (non-patented). This was performed by us in ourexperimental orchard which is located near Fowler, Calif. Subsequentannual evaluations have shown those asexual reproductions run true tothe original tree. All characteristics of the original tree, and itsfruit, were established and appear to be transmitted through succeedingasexual propagations. We have observed fruit for the past 4 successiveyears from approximately 15 propagated trees.

SUMMARY OF THE VARIETY

‘Burnectthirteen’ is a new and distinct variety of nectarine tree, whichis considered of large size, and which has vigorous growth. This newnectarine tree variety is also a regular and productive bearer ofrelatively large, firm, sub-acidic white fleshed, clingstone fruit,which have good flavor and eating quality. The tree of the presentvariety displays a chilling requirement of approximately 500 hours.Still further the tree also produces relatively uniformly sized fruitthroughout the entire tree. Still further, the fruit have a high degreeof red skin coloration, and a firm flesh. In addition to the foregoing,the fruit of this new tree also appears to have good handling andshipping qualities. The ‘Burnectthirteen’ Nectarine tree bears fruitwhich are ripe for commercial harvesting and shipment on approximatelyMay 24 to June 4 under the ecological conditions prevailing in the SanJoaquin Valley of central California. In relative comparison with the‘Crimson Baby’ nectarine tree, which is the seed parent, the present newvariety of nectarine tree bears fruit which ripen about 5 to 8 daysearlier, and further is white fleshed.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing, which is provided, is a color photograph ofthe new variety of nectarine tree. It depicts two whole mature fruit,and one mature fruit dissected substantially in the equatorial plane,and viewed from the apical perspective, to reveal the flesh colorationand the stone thereof. The external coloration of the fruit is shownsufficiently matured for harvesting and shipment. Additionally thephotograph displays a sample vegetative shoot bearing typical leaves,and a typical stone, with the fleshed removed. The colors in thisphotograph are as nearly true as is reasonably possible in a colorrepresentation of this type. Due to chemical development, processing andprinting, the leaves and fruit depicted in these photographs may or maynot be accurate when compared to the actual specimens. For this reason,future color references should be made to the referenced color plates(Royal Horticultural Society) and the descriptions provided hereinafter.

DETAILED DESCRIPTION

Referring more specifically to the pomological details of this new anddistinct variety of nectarine tree, the following has been observedduring the fourth fruiting season under the ecological conditionsprevailing at orchards located near the town of Fowler, county ofFresno, state of California. All major color code designations are byreference to The R.H.S. Colour Chart (Fourth Edition) provided by TheRoyal Horticultural Society of Great Britain. Common color names arealso occasionally used.

Tree:

Size.—Generally — Considered medium-large as compared to other commoncommercial nectarine cultivars ripening in the early season of maturity.The tree of the present variety was pruned to a height of approximately270.0 cm to about 300.0 cm at maturity.

Vigor.—Considered vigorous. The present nectarine variety grew fromabout 159.0 cm to 171.0 cm in height during the first growing season.The new nectarine tree variety was pruned to a height of approximately150.0 cm during the first dormant season, and primary scaffolds werethen selected for the desired tree structure.

Productivity.—Productive. Fruit set varies from twice to several timesmore than the desired crop load. Fruit set is spaced by thinning todevelop the remaining fruit into the desired market size. The number offruit set varies with the prevailing climatic conditions, and culturalpractices employed during the bloom period and is therefore notdistinctive of this new variety.

Bearer.—Regular. Fruit set has been heavy and thinning was necessaryduring the past 5 years.

Form.—Upright, and pruned to a vase shape.

Density.—Considered medium dense. It has been discovered that pruningthe branches from the center of the tree to obtain a resulting vaseshape allows for air movement and appropriate amounts of sunlight toenhance the resulting fruit color and renewal of fruiting woodthroughout the tree.

Hardiness.—The present tree was grown and evaluated in USDA HardinessZone 9. Winter chilling requirements of the new tree are approximately500 hours below 7.0 degrees C. The variety also appears to be hardyunder typical central San Joaquin Valley climatic conditions.

Trunk:

Diameter.—Approximately 13.0 cm in diameter when measured at a distanceof approximately 15.24 cm above the soil level, at the end of the fifthgrowing season.

Bark texture.—Considered moderately rough, with numerous folds of paperyscarfskin being present.

Lenticels.—Numerous flat, oval lenticels are present. The lenticelsrange in size from approximately 4.0 to about 7.0 millimeters in width,and from about 1.0 to about 2.0 millimeters in height.

Lenticel color.—Considered an orange brown, (RHS Greyed Orange Group 165B).

Bark coloration.—Variable, but it is generally considered to begray-brown, (RHS Brown Group 200 D).

Branches:

Size.—Considered medium for the variety.

Diameter.—Average as compared to other nectarine tree varieties. Thebranches have a diameter of about 5.5 centimeters when measured duringthe fifth year following grafting.

Surface texture.—Average, and appearing furrowed on wood, which isseveral years old.

Crotch angles.—Primary branches are considered variable between about 44to 51 degrees from the horizontal axis. This particular characteristicis not considered distinctive of the variety however.

Current season shoots.—Surface texture — Substantially glabrous.

Internode length.—Approximately 2.4 to about 2.7 cm. This treecharacteristic is highly dependent upon plant nutrition, soil quality,pruning and tree care and therefore is not distinctive of the variety.

Color of mature branches.—Medium brown, (RHS Greyed Orange 165 A).

Current seasons shoots.—Color — Light green, (RHS Yellow Green GroupN144 B). The color of new shoot tips is considered a bright and shinygreen (RHS Yellow-Green Group 143 B).

Leaves:

Size.—Considered medium to large for the species. Leaf measurements havebeen secured from vigorous, upright, current-season growth taken atapproximately mid-shoot.

Leaf length.—Approximately 142.0 to 158.0 millimeters.

Leaf width.—Approximately 37.0 to about 42.0 millimeters.

Leaf base shape.—Slightly oblique relative to the leaf longitudinalaxis.

Leaf form.—Lancelolate.

Leaf tip form.—Acuminate.

Color.—Upper Leaf Surface — Dark green, (approximately RHS Green Group136 B).

Leaf texture.—Glabrous.

Color.—Lower Leaf Surface — Medium green, (RHS Green Group 137 A).

Leaf venation.—Pinnately veined.

Mid-vein.—Color — Light green, (RHS Green Group 143 C).

Leaf margins.—Slightly undulating. Form — Considered crenate,occasionally doubly crenate. Uniformity — Considered generally uniform.

Leaf petioles.—Size — Considered medium-long. Length — About 7.0 toabout 10.0 mm. Diameter — About 2.0 to about 2.5 mm. Color — Pale green,(RHS Yellow Green Group 145 A).

Leaf glands.—Size — About 1.0 mm in height and about 2.0 mm in width.Number — Generally one per side, occasionally two per side. Type —Reniform, and considered reasonably unappressed relative to the petiolemargin. The leaf glands are considered moderately small. Color — Orangebrown, (RHS Greyed Brown Group N199 D).

Leaf stipules.—Size — Average for the variety. Number — Typically 2 perleaf bud, and up to 6 per shoot tip. Form — Lanceolate in form, andhaving a serrated margin. Color — Green, (RHS Yellow Green Group 145 A)when young, but graduating to a brown color, (RHS Greyed Orange group166 C) with advancing senescence. The stipules are considered to beearly deciduous.

Flowers:

Flower buds.—Generally — The floral buds, depending upon the stage ofdevelopment are approximately 7.0 millimeters wide; and about 11.0millimeters long; conic in form; and slightly appressed relative to thebearing shoot.

Flower buds.—Color — The bud scales are reddish-brown, (approximatelyRHS Greyed Purple Group 183 B). The buds are considered hardy undertypical central San Joaquin Valley climatic conditions.

Hardiness.—No winter injury has been noted during the last several yearsof evaluation in the central San Joaquin Valley. The current variety hasnot been intentionally subjected to drought or heat stress and thereforethis information is not available.

Date of first bloom.—Feb. 22, 2002.

Blooming time.—Considered early mid-season in relative comparison toother commercial nectarine cultivars grown in the central San JoaquinValley. Date of full bloom was observed on Feb. 27, 2002. The date ofbloom varies slightly with the prevailing climatic conditions andcultural practices.

Duration of bloom.—Approximately 10 days. This characteristic variesslightly with the prevailing climatic conditions.

Flower type.—The variety is considered to have a showy type flower.

Flower size.—Flower diameter at full bloom is approximately 41.0 toabout 43.0 millimeters.

Bloom quantity.—Considered very abundant.

Flower bud frequency.—Normally 1 to 2 flower buds appear per node.Rarely 3 buds per node may be observed.

Petal size.—Generally — Considered large for the species. Length —Approximately 19.0 to about 21.0 millimeters. Width — Approximately 18.0to about 21.0 millimeters.

Petal form.—Rotund.

Petal count.—Generally 5. Occasionally individual flower pedal countsare doubled.

Petal texture.—Glabrous.

Petal color.—Light pink, (RHS Red Purple Group 62 C) to a medium pink,(RHS Red Purple Group 58 D).

Fragrance.—Slight.

Petal claw.—Form — The petal claw is considered truncate in shape, andhas a large size when compared to other varieties. Length —Approximately 8.0 to about 10.0 millimeters. Width — Approximately 9.0to about 11.0 millimeters.

Petal margins.—Generally considered variable, from nearly smooth, tomoderately undulate.

Petal apex.—Generally — The petal apices appear entire and without anapical groove.

Flower pedicel.—Length — Considered medium-long, and having an averagelength of approximately 3.0 to about 4.0 millimeters. Diameter —Considered average, approximately 2.0 millimeters. Color — A reddishbrown, (RHS Greyed Purple Group 183 C).

Floral nectaries.—Color — A pale green, (RHS Yellow Green Group 153 D).

Calyx.—Surface Texture — Generally glabrous. Color — A dull red,(approximately RHS Greyed Purple Group 183 A).

Sepals.—Surface Texture — The surface has a short, fine pubescenttexture. Size — Average, and ovate in form. Color — A dark reddishpurple, (approximately RHS Greyed Purple Group 183 B).

Anthers.—Generally — Large in size. Color — Reddish purple,(approximately RHS Greyed Purple Group 183 B).

Pollen production.—Pollen is abundant, and has a yellow color,(approximately RHS Yellow Group 12 A).

Filaments.—Size — Variable in length, approximately 16.0 to 19.0millimeters. Color — Considered pink, (RHS Red Purple Group 62 B).

Pistil.—Number — Usually 1, occasionally 2. Generally — Average in size.Length — Approximately 16.0 to about 19.0 millimeters including theovary. Color — Considered a very pale green, (approximately RHS YellowGreen Group 149 D). Surface Texture — The variety has a long glabrouspistil.

Fruit:

Maturity when described.—Firm ripe condition (shipping ripe). Date offirst picking — May 24, 2002. Date of last picking — Jun. 4, 2002. Thedate of harvest varies slightly with prevailing climatic conditions.

Size.—Generally — Considered relatively large, and uniform.

Average cheek diameter.—Approximately 68.0 to about 74.0 millimeters.

Average axial diameter.—Approximately 69.0 to about 73.0 millimeters.

Typical weight.—Approximately 205.0 grams. This characteristic is highlydependent upon cultural practices and therefore is not particularlydistinctive of this new variety.

Fruit form.—Generally — Rounded. The fruit is generally uniform in itssymmetry.

Fruit suture.—Shallow, and extending from the base to the apex. Noapparent callousing or stitching exists along the suture line.

Suture.—Color — The background color appears to be the same as the blushcolor, that is, graduating from a light red (approximately RHS Red Group44 A) to a dark red purple, (approximately RHS Greyed Purple Group 187A).

Ventral surface.—Form — Slightly indented.

Apex.—Rounded.

Base.—Retuse.

Stem cavity.—Rounded and relatively shallow. The average depth of thestem cavity is about 1.55 cm. The average width of the stem cavity isabout 1.94 cm.

Fruit skin.—Thickness — Considered medium in thickness, and tenacious tothe flesh. Texture — Short, fine, and glabrous. Taste — Non-astringent.Tendency to crack — Not observed. Occasional russeting has beenobserved.

Color.—Blush Color — This red blush color is variable from a reddishorange, (approximately RHS Red Group 44 A) to a dark red, (approximatelyRHS Greyed Purple Group 187 A). The blush color ranges from about 75% toabout 95% of the fruit surface depending upon the sunlight exposure andprevailing growing conditions. Ground Color — Generally a light yellow,(approximately RHS White Group 155 A).

Fruit stem.—Moderate in length, approximately 50.0 to about 67.0millimeters. Diameter — Approximately 2.0 to about 3.0 millimeters.Color — Brown, (approximately RHS Greyed Orange Group 164 C).

Flesh.—Rippens — Evenly. Texture — Firm, and dense. Considered melting.Fibers — Few, small, and tender ones are found. Aroma — Slight. EatingQuality — Considered very good. Favor — Considered sweet and sub-acidic.The flavor is viewed as both pleasant and balanced. Juice — Moderate.Brix — About 17.5 degrees. This plant characteristic varies slightlywith the number of fruit per tree; the prevailing cultural practices;and the surrounding climatic conditions. Flesh Color — Pale white,(approximately RHS White Group 155 D).

Stone:

Type.—Clingstone.

Size.—Considered medium-large for the variety. The stone size varieswith the resulting crop load, and tree vigor, and is therefore notconsidered a distinguishing characteristic of this new variety.

Length.—Average, about 23.5 to about 25.0 millimeters.

Width.—Average, about 21.0 to about 22.0 millimeters.

Diameter.—Average, about 17.0 to about 21.0 millimeters.

Form.—Obovoid.

Base.—The stone base is usually oblique relative to the stone's verticalaxis.

Apex.—Shape — The stone apex is raised and has an acute, protruding tip.

Stone surface.—Surface Texture — This surface texture is characterizedby a concentric ridge/furrow pattern which begins at the margins.Substantial grooving over the apical shoulders is evident. Surfacepitting is less generally noted than the ridges or furrows, but is morefrequently observed in the mid-section of the stone. Substantial erosionis usually observed along the stone margin and near the tip on theventral side thereof. Ridges — The surface texture varies from sharp torounded. Ventral Edge — Width — Considered average, and having adimension of approximately 2.0 to about 4.0 millimeters when measured atthe mid-suture. The wings are most prominent over the suture line.Dorsal Edge — Shape — Full, heavily grooved, and having jagged edges.

Stone color.—The color of the dry stone is a light brown, (approximatelyRHS Greyed Orange Group N170 C).

Tendency to split.—Occasional splits have been noted.

Kernel.—Size — The kernel is considered immature and gelatinous. Form —Considered ovoid. Pellicle — Pubescence. Color — Considered to be a palebrown (Approximately RHS Yellow White Group 158 A).

Use.—The subject variety ‘Burnectthirteen’ is considered to be aNectarine tree of the early season of maturity, and which producesfruit, which are considered firm, attractively colored, and which areuseful for both local and long distance shipping.

Keeping quality.—Excellent. Fruit has stored well for up to 25 daysafter harvest at 1.0 degree Celsius.

Shipping quality.—Good. The fruit of the new nectarine tree varietyshowed minimal bruising of the flesh or skin damage after beingsubjected to normal harvesting and packing procedures.

Resistance to insects and disease.—No particular susceptibilities werenoted. The present variety has not been tested to expose or detect anysusceptibilities or resistances to any known plant and/or fruitdiseases.

Although the new variety of nectarine tree possesses the describedcharacteristics when grown under the ecological conditions prevailingnear Fowler, Calif., in the central part of the San Joaquin Valley ofCalifornia, it should be understood that variations of the usualmagnitude and characteristics incident to changes in growing conditions,fertilization, pruning, pest control and horticultural management are tobe expected.

Having thus described and illustrated our new variety of nectarine tree,what we claim is new and desire to secure by Plant Letters Patent is: 1.A new distinct variety of nectarine tree, substantially as illustratedand described, and which is characterized principally as to novelty byproducing an attractively colored white-fleshed, sub-acid clingstonenectarine which is mature for harvesting and shipment approximately May24 to June 4 under the ecological conditions prevailing in the SanJoaquin Valley of Central California.